An Evaluation of Physicochemical Treatment Technologies for Water Contaminated with MTBE

• Published in: Ground water monitoring & remediation 2000-11, Vol.20 (4), p.114-126
• Main Authors: Keller, Arturo A., Sandall, Orville C., Rinker, Robert G., Mitani, Marie M., Bierwagen, Britta, Snodgrass, Michael J.
• Format: Article
• Language: English
• Subjects: MTBE
• ISSN: 1069-3629; 1745-6592
• DOI: 10.1111/j.1745-6592.2000.tb00296.x

Treatment of methyl tertiary‐butyl ether (MTBE) from contaminated surface and ground water supplies presents specific challenges due to the physicochemical properties of MTBE that depend strongly on its hydrophilic nature, and translate into a high solubility in water, and low Henry's constant and low affinity for common adsorbents. We evaluate four treatment technologies‐air stripping, granular activated carbon (GAC), hydrophobic hollow fiber membranes, and advanced oxidation processes (AOP)‐using ozone or ozone/hydrogen peroxide. Experimental work was carried out to generate parameter values necessary for the design of these processes. Ten different flow rates/concentration combinations were evaluated in our designs to cover the range from high flow rate/low concentration typical of surface water and ground water drinking water supplies to low flow rate/high concentration typical of ground water remediation sites. For all cases, the processes were designed to produce effluent water of 5 μg/L or less. Capital costs and operation and maintenance costs were determined at the feasibility level by using standard engineering estimating practices. Air stripping is the lowest cost technology for high flow rales (100 to 1000 gpm) if no air treatment is required. Hollow fiber membranes are the lowest cost technology for flow rates of 10 to 100 gpm if no air treatment is required, which is typical at these low flow rates. GAC will be most costeffective at all flow rates if air treatment is required and the influent water has low levels of other organic compounds. AOP using ozone or ozone/hydrogen peroxide is in all cases more expensive than the alternative technologies, and there are sufficient uncertainties at this point with respect to byproducts of AOP to warrant further study of this technology. The cost of treating MTBE‐contaminated water for conventional technologies such as air stripping and GAC is 40% to 80% higher than treating water contaminated only with other hydrocarbons such as benzene.